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Today, we say goodbye to Sherlock Holmes (for the rest of the series, on the importance of true observation, seeing what isn’t there and not just what is, and preventing your mind from growing cluttered, please see the links). It’s not that there’s a shortage of valuable psychological lessons to be gleaned from his stories. Quite the opposite. There are so many that even a far longer series couldn’t hope to cover them all. To that end, I devote the rest of this post to a few outstanding lessons that I have found to be valuable in my constant quest to become a better, more mindful and more precise decision maker.

In “The Boscombe Valley Mystery,” Holmes admonishes Watson: "You know my method. It is founded upon the observance of trifles.”

Nothing is too small, and often, the things we ignore end up being crucially important. This lesson echoes the first in the series, the importance of real observation. But it is central enough to mindful decision making that it bears repeating. And it is equally important to realize that seeing entails the use of every sense, not just your eyes. Each input holds important information. Don’t ignore it, and don’t discard it.

However, it is instructive to also keep in mind a corollary to this rule: not every small thing is actually important. In “A Case of Identity,” Holmes asks Watson what he remarked about the appearance of a visitor. When Watson shares his impressions, Holmes responds: "'Pon my word, Watson, you are coming along wonderfully. You have really done very well indeed. It is true that you have missed everything of importance, but you have hit upon the method, and you have a quick eye for color. Never trust to general impressions, my boy, but concentrate yourself upon details."

Paying attention to what doesn’t matter is not quite as bad as not paying attention at all, but is still infinitely worse than approaching your observation in a more mindful way (in other words, understanding enough about your purpose to learn to distinguish the actual trifles from the trifles that aren’t).

Lesson 2: Remember to change your perspective from time to time

In “The Boscombe Valley Mystery,” Holmes lays out the particulars of a crime, whereupon Watson comments, “I could hardly imagine a more damning case. If ever circumstantial evidence pointed to a criminal it does so here.” But not so fast. As Holmes responds, "Circumstantial evidence is a very tricky thing. It may seem to point very straight to one thing, but if you shift your own point of view a little, you may find it pointing in an equally uncompromising manner to something entirely different."

Perspective matters. Often, insight into anything, from a criminal case to a simple, everyday decision, requires a willingness to look at something from another angle, consider alternate theories and alternate points of view. Indeed, openmindedness and imagination (something Holmes further applauds in “Silver Blaze”) is often remarkably close to mindfulness – and its opposite, to mindlessness.

Even the great detective himself needs a change of perspective every so often:

"Do you know, Watson," said he, "that it is one of the curses of a mind with a turn like mine that I must look at everything with reference to my own special subject. You look at these scattered houses, and you are impressed by their beauty. I look at them, and the only thought which comes to me is a feeling of their isolation and of the impunity with which crime may be committed there."

As Holmes has astutely observed (in “The Adventure of Copper Beeches”), sometimes, even the best of us have a hard time shifting gears. And while often, it doesn’t really matter, there are times when the very shift is the precursor to the moment of greatest insight.

Lesson 3: Don’t decide before you decide

When, in “A Scandal in Bohemia,” Watson asks Holmes as to his theory on the King of Bohemia’s problem, Holmes responds, "I have no data yet. It is a capital mistake to theorize before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts."

It’s remarkable how often we do in fact form a theory prior to knowing all of the particulars. In other words, we decide before we decide.

It can be anything from a first impression of a person (a common observation, for instance, is that interviewers make up their minds about a candidate within the first three minutes of a conversation) to a decision taken based on some broad principle, which then prompts a hasty search for validating information, that yes, it was in fact the correct one—and a concomitant discarding of any evidence to the contrary. That tendency even has a name in the psychological literature: confirmation bias. It is common, and it clouds judgments. If you dismiss anything that doesn’t fit, your view of the world becomes a warped one, indeed. (As a side note, I wish more politicians and die-hard politicos would keep this lesson in mind).

Lesson 4: Use sound logic and be wary of false leaps

In “The Adventure of the Noble Bachelor,” Inspector Lestrade tells Holmes his conclusions on some existing evidence: "They have been identified as her clothes, and it seemed to me that if the clothes were there the body would not be far off." Holmes’s response is not as enthusiastic as Lestrade might have hoped. He says,

“By the same brilliant reasoning, every man's body is to be found in the neighborhood of his wardrobe.”

Here, the lesson is fairly self-explanatory. Beware of logical leaps that are, well, illogical. What seems to be the case may not be the case at all. Also a valuable lesson to remember as you listen to people lay out their arguments to you. You will be much more able to spot holes in reasoning if you keep to strict principles of logic yourself.

Lesson 5: Thinking you’ve thought something through and actually thinking it through are two very different things

In “Silver Blaze,” Holmes tells Watson, "Nothing clears up a case so much as stating it to another person."

Logical gaps are easy to overlook in your own mind. Speaking a stream of thoughts aloud, committing them to paper, talking them through—if only to yourself—will help you make sure that you’ve actually thought something through to the fullest. Clarity of language breeds quality of thought.

Lesson 6: Don’t forget to remain humble; there’s always more to learn

Holmes wants to make sure he doesn’t become his own worst enemy. As he tells Watson in “The Yellow Face:” "If it should ever strike you that I am getting a little over-confident in my powers, or giving less pains to a case than it deserves, kindly whisper 'Norbury' in my ear, and I shall be infinitely obliged to you."

Even the great Holmes knows his limits and knows when a gentle reminder might be in order. Overconfidence, closely related to what the Greeks terms hubris, often leads to mistakes, rash judgments, and general blundering. Many a great mind have fallen prey to that error.

As Holmes reminds Watson, in “The Adventure of the Red Circle,” "Education never ends, Watson. It is a series of lessons with the greatest for the last."

Lesson 7: Words count for nothing without action

In “The Adventure of the Greek Interpreter,” we are introduced to Holmes’s brother, Mycroft. When Watson wonders why, though Mycroft has better powers of observation than Holmes himself, he has not become a detective, Holmes responds, "I said that he was my superior in observation and deduction. If the art of the detective began and ended in reasoning from an arm-chair, my brother would be the greatest criminal agent that ever lived. But he has no ambition and no energy. He will not even go out of his way to verify his own solution, and would rather be considered wrong than take the trouble to prove himself right."

Here, Holmes makes an important distinction. Talking and acting are not one and the same. You can be the best armchair anything in the world, but unless you have the drive, the persistence, the spark and the commitment that will take your musings from the chair and into the world, it means nothing. This is something of which I often need to remind myself. Talk is cheap. Do it already. (I should really tape this one to my computer screen; that’s how often I forget it and how important I think it is to remember).

Lesson 8: Distraction is not your friend

In “The Hound of the Baskervilles,” Watson opens a window for some fresh air. Soon, however, Holmes asks if he might once again close it. As he explains it, "It is a singular thing, but I find that a concentrated atmosphere helps a concentration of thought. I have not pushed it to the length of getting into a box to think, but that is the logical outcome of my convictions."

Blocking out distraction is important not just in making decisions, but in most everything you do. When we want to think outside the box, we might do well to first, make our own box as small as possible, as free as possible of outside interference. Especially with the lure of the internet, distraction is a constant threat – and I fight it all the time. However you manage your own distraction, it is important to remember that it can seriously interfere with a meaningful thought process.

It’s crucial, however, to distinguish between distraction and a well-timed break, one that comes after hours of concentration. The former is to be avoided. The latter can lead to the so-called eureka moment, when a previously intractable problem is suddenly clear.

Lesson 9: Don’t underestimate the importance of broad knowledge

In “The Adventure of the Golden Pince-Nez,” Sherlock Holmes exchanges the following remarks with Stanley Hopkins, when the latter arrives in his office:

“It must be something important which has brought you out in such a gale."

"It is indeed, Mr. Holmes. I've had a bustling afternoon, I promise you. Did you see anything of the Yoxley case in the latest editions?"

"I've seen nothing later than the fifteenth century today."

Holmes’s job is to be on top of the most breaking of breaking news, but he always finds the time for a fifteenth century abbey. Never become so focused on what you do and what you think you need to know that you forget to take a moment to step back. It’s surprising how often insights can come from something you never thought to relate to the problem at hand. But for that to be the case, you need to keep your base of knowledge broad and ever-expanding.

Lesson 10: Above all, think

The final lesson is from “The Valley of Fear.” In the opening lines of the story, Watson is cut off mid-remark:

"I am inclined to think—" said I.

"I should do so," Sherlock Holmes remarked impatiently.

Don’t bother with preliminaries. Don’t waste time. Don’t let your mind become lazy, even in the most mundane of occupations. Never remain inclined to think. Just think.

Holmes bids farewell

Sherlock Holmes is one of the most mindful decision makers of all times. Every choice is thought out, motivated, based on detailed observation and meticulous analysis, unclouded by emotion or the vagaries of the moment. Holmes is an extreme type. He’s allowed to be—after all, he is fictional. I am far from suggesting we become exactly like him. But as such precise resemblance is impossible, we need not fear the coldness of its implications. Instead, we can strive to emulate his habits of thought and observation as closely and as artfully as we can. Maybe then, we will learn to observe, in the true sense of the word.

If you want Holmes to return to the blog, please let me know in the comments or by email, and I will do my best to respond. His wisdom can certainly take up countless posts – and it wouldn’t be the first time the great detective was brought back from the dead.